Foam earplugs have been generally well accepted for providing sound attenuation. Such earplugs are generally cylindrical in shape and of somewhat larger diameter than the human ear canal. The earplugs may be composed of a foamed plasticized polymeric material having a sufficiently high concentration of plasticizer to provide the earplug with a reduced rate of recovery from compression. The earplugs can be compressed by twirling lengthwise between the fingers. The compressed earplug is inserted into the ear canal where it then recovers slowly until it conforms to and obturates the ear canal, thus suppressing or attenuating the transmission of noise.
To aid in compression of earplugs, an earplug may be encased in an envelope of thin flexible plastic material which extends lengthwise beyond the end of the earplug. The envelope is twistable to compress the earplug and thereby reduce its size to facilitate introduction of the earplug into the ear canal. The envelop can be open to the atmosphere to permit air to be expelled when the envelop is compressed and twisted, or the envelop can be sealed and evacuated.
Earplugs have been provided as units with an inserter and tie which can be worn as a unit. The earplugs having a relatively flexible stem and adjacent spaced flanges of varying size made of relatively soft, yieldable, resilient material which readily conform to the ear canal. Each earplug has outer end attached to a tie member on which is slideably carried and retained an earplug inserter. The earplug inserter is movable from a carrying position into engagement with the outer end of an earplug for its insertion into the ear canal.
A combined protective case and inserter for earplugs having flanges has been disclosed. The case includes cover which can be held in a closed or an open position. The cover can be positioned such that either one of two earplug inserting means are exposed for aiding in insertion of the earplug into a users ear.
An earplug compression device for slow recovery earplugs is also known. The device has a flexible strip and a base, the flexible strip being fastened at one end to the base with the other end passing through a slot in the base to form a tubular compression means. An earplug is placed within the device and tension is applied to the unattached end of the flexible strip to compress the earplug for insertion in an ear canal.